


The One Where Cas Finds Out

by AnEqualOpportunist



Category: Supernatural
Genre: Alpha Castiel, Alpha/Beta/Omega Dynamics, Alternate Universe - High School, M/M, Omega Dean, Omega Verse
Language: English
Status: Completed
Published: 2013-11-17
Updated: 2013-11-17
Packaged: 2018-01-01 21:32:22
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,490
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1048801
Author URL: https://archiveofourown.org/users/AnEqualOpportunist/pseuds/AnEqualOpportunist
Summary: <blockquote class="userstuff">
      <p>Lovingly half beta'd by my dear friend Cordelia (angelmagnet on tumblr, check her out). I panicked and posted before she could do the other half. Feed back is always appreciated.</p>
    </blockquote>





	The One Where Cas Finds Out

**Author's Note:**

> Lovingly half beta'd by my dear friend Cordelia (angelmagnet on tumblr, check her out). I panicked and posted before she could do the other half. Feed back is always appreciated.

Dean’s eyes snapped open. Wrapped in sticky sheets, he reached for his phone to check the date. After a few calculations, he realized he was three days early. He had hoped he’d make it to the weekend. But Fate is a heartless Bitch. He would be missing the rest of the week, but he could get Cas and Benny to get him his homework. Cas might even do some of it for him. Shit. Thinking of the Alpha wasn’t helping his situation any. He needed to get everything sorted before his heat got too strong. He started to dial.

“Hello?” A gruff voice answered. Dean took a few breaths to calm down.

“Hey, Cas. I’m sick. Can you get my homework and give it to Benny to bring over?”

“Dean are you playing hooky again? That’s the fourth time this year?”

“No, I’m really sick this time.”

“Fine, I’ll bring your homework this evening.”

“Nonono, just  give it to Benny. He’s just next door. I don’t want you going out of your way.”

“Dean, it’s really not a problem.”

“Cas, seriously, just have Benny bring it over.” Dean snapped. Cas was going to be offended. Dean would make it up to him after his heat was over and the house had been cleaned.

“Very well, Dean. I will have Benny bring it to you. I hope you feel better soon.” Cas hung up.

“Thanks, Cas…” Dean mumbled to the dead line. Dean could feel his heat rising. He shot off a text to Benny.

_Heat hit early. Get hmwk from Cas._

_Again? Why don’t you just tell him your omega?_

_And lose my best friend? No thanks._

_That make me feel good, Dean. Real good._

_You know what I mean, Benny._

_Yeah, yeah, Have a nice heat_

_Not possible._

_Sure it is, read the new Batman I got you._

_I’ll be too busy shoving something up my ass to enjoy it_

_TMI, brother. TMI_

_You sound like Sam_

_Want him to stay over for the week?_

_Nah. Mom’s home, should be fine_

_Awesome, see you tonight_

Dean didn’t respond, instead going to shower. He couldn’t feel the temperature, but he felt cleaner as the water poured over him. When he decided that the slick between his legs wasn’t going away soon, he shut the water off and pulled an old shoe box from the top shelf of his closet. He dropped his towel and flopped on his bed. Opening the box and reaching under the Aquaman comics to pull out his fake knot. Closing the box and sliding it under the bed, he rolled the knot in his hand. It wasn’t what he or his body wanted but it would have to do until he was mated.

His Omega mom would be able to tell he was in heat and keep Sammy away, the nosey brat. She’d make sure he’d eat and drink and all those things his mate was supposed to do. But since he didn’t have a mate, his mom would have to do. He wondered what his mate would be like. As he circled his hole with the toy. He thought of strond hands. Toned arms. Muscular. Dark hair. Blue eyes.

“Cas…” Dean sighed out, finally slipping the toy in with a wimper.

Castiel, as requested, got all of Dean’s homework from their teachers, even breaking into Dean’s locker to get the books he’d need. He dropped the pile on the bench in front of Benny in the locker room.

“I  assume Dean contacted you?” Cas scowled.

“Yeah, I told Coach we have to do without our trusty manager today, too.”

“Excellent.” Castiel started changing into his soccer kit, more than a little irritated.

“Hey, Cas. What’s the matter?”

“I simply do not understand why Dean does not wish to see me.”

“That’s not it at all!” Benny assured, trying to calm the alpha down. “He wants to see you, believe me… He’s just… sick.”

“Why is it okay for you to see him then?”

The Beta hesitated. “Just something we Betas understand,”

Cas rolled his eyes and stalked out of the locker room.

There was a knock on the door. Dean groaned an answer, acknowledging his decency. His mother entered with a tray of food, a large bottle of water, and followed by Benny laden with books. His mother set the tray on the bedside table and left.

“Man, you reek”

“Thanks, Benny…” Dean mumbled from under the blankets.

“You should tell him, you know. He’d probably take your heat. If not, he’d at least feel less left out.”

“No”

“Dean.”

“Benny, if he did take my heat, he’d do it out of obligation. He doesn’t feel that way about me.”

“Bull. You two are practically mated already”

“Benny, I-“ Dean stopped, letting out a pained moan as another wave of heat washed over him. “I am hormonal and pissed about this fucking fake knot, so unless you plan on miraculously poppin one now, get out.”

Benny turned and ran. Shouting a “See ya, Mrs. Winchester” as he closed the front door.

Castiel watched from his car as Benny walked down the street to his own house. Once he deemed Benny a safe distance away, he grabbed the textbook he had “Forgotten" to give Benny and walked up to the Winchester’s front door and knocked.

The door opened just a touch, revealing the face of Mary Winchester.

“Castiel! I thought Dean told you he was sick!” Mary looked nervous.

Castiel held up the textbook and took a deep breath. He stopped. Sniffed again. Omega. But it wasn’t Mrs. Winchester, it wasn’t strong enough for how close she was. Sam was too young to know his designation. Which left…

“Dean…” Castiel gasped.

Mary realized what was happening. "Cas! Hey, Cas! Focus on me! You need to go home. Calm down. Come back on Sunday." 

Castiel was halfway down the driveway by the time she was done, only slightly impeded by the hard on in his pants. He got in his car and took several deep breaths. Dean was an Omega. Not a beta. It made so much more sense now. He was "sick" every few months. Never showed much interest in anyone. He was waiting for a mate. Why didn't Dean trust him? Did he think Cas would take advantage of him? Try and mate with him? Dean should know better. Castiel would never mate with him unless Dean wanted him to, no matter how badly Cas wanted to claim the beautiful boy. Oh. Dean didn't want him. He probably merely tolerated his annoying alpha friend. Well, then. Cas wouldn't bother the omega any longer.

***

Dean heard the knock on the front door. Then he smelled it. Alpha. He flung his fake knot aside and ran to his bedroom door, only to find it locked from the outside. He clawed at the door, banging on it, crying out to try and get the Alpha's attention. It didn't work. The beautiful, gorgeous, dominate smell of Alpha weakened before it was completely over whelmed by disinfectant. At the loss, he fell to the ground, whimpering. The door was unlocked and his mother poked her head in. 

"Are you okay, Dean? That had to be difficult for you..."

Big understatement. 

"He'll come back on Sunday, after we clean up the house. We'll explain everything and discuss how to move forward. It'll be okay. I promise." She left.

Dean rolled over and reached for the discarded knot. It would be a long heat.

***

Sunday came and went without any visitation from Castiel. Dean cleaned his room three times and tried to arrange his bedroom into a suitable den. Typically the alpha's job, but Dean was too busy panicking over the lack of alpha to care. His mother finally made him stop cleaning and work on his homework that Benny had faithfully dropped off. 

***

Dean entered school on Monday, his eyes peeled for Castiel. Once he caught his eye, but the alpha basically ran away. By the end of the day, Dean was extremely frustrated with Cas. When the final  bell rang, Dean made it to Castiel's car before Cas could. The alpha started to turn away, but the omega caught up. 

"Damnit, Cas. What's going on? You were supposed to come over yesterday..." 

"It is obvious that you do not trust me and no longer wish to associate with me. I was simply making it easier on you." 

"What the hell gave you that idea?"

"You didn't trust me enough to tell me of your designation. You thought I would rape you, Dean. What am I supposed to think?"

"That's not true at all..." Dean's face fell.

"Then why didn't you tell me?!" Cas shouted, drawing the attention of a group of people down the row.

"I... I didn't think you'd rape me, Cas... I was... I wanted... You... I wanted you to take my heat, but I was afraid you'd feel obligated... And you don't feel that way about me... I never wanted another Alpha, so I just hid my designation..." Dean admitted.

Cas was shocked. "You- You wanted me to- to take your heat?" He asked dubiously.

Dean nodded. "When you came over and I smelled you... I couldn't control myself... I tried breaking down the door, I just wanted you... My alpha..." Dean couldn't take his eyes off the ground. 

Cas took a step forward. "Dean..."

"It's okay, Cas. You know now. Three more months, and it'll happen again. Give my homework to Benny and tell Coach I won't be at practice." 

Dean began to walk away. He was stopped by Cas grabbing his shoulder. Dean was pulled into  the alpha's arms. Cas buried his face into Dean's neck. Dean was confused and tried to push Cas away. The alpha simply tightened his arms. Then, Dean got it. Cas was scenting him. 

"Cas..." Dean sighed.

Cas hmmed into his neck. Breathing in Dean's scent and spreading his own. 

"Cas, come home with me..."

Castiel pulled and shoved Dean into his car. Alpha instincts taking over. Usually, Cas was a very safe driver. However, in his current state, he didn't care much. The omega next to him was taking on his scent. He could tell that Dean's arousal rivaled his own. The got to the Winchester house in record time. Dean leaped across the front seat and buried his nose in his Alpha's neck the second the car was in park. Cas opened the door and pulled his friend out, supporting most of Dean's weight, as was his duty as Alpha. They somehow got through the door and into Dean's room, high on the pheromones they were putting out. Mary was at work and Sam still at school, they wouldn't be interrupted. Cas dropped Dean onto the bed and the omega tried to pull him down. Scenting was the most important and the most intimate part of mating. Dean wanted to be as thorough as possible. Castiel pulled of their shirts. He scented down Dean's arms and across his torso. With his arms wrapped around Dean's waist, he kissed back up, spending extra time at the omega's neck, where the scent was the strongest. "Cas..." Dean groaned out. The alpha tightened his grip at the sound. He looked into Dean's eyes. Lust blown. Cas hesitated just a moment before finally kissing Dean. Ever since he had manifested, he had wanted to kiss Dean's plush lips. And finally, finally he was allowed to. They were gonna be mated now. Cas palmed the front of Dean's jeans, undoing them before he was ripped away from Dean and flung against a wall. He was face to face with John Winchester. 

"What are you doing here, Cas?" He growled at the younger Alpha. Dean was on his feet and pulling at the arm that was cutting off Castiel's airway. "Leave him alone, Dad. He can't breathe!" 

John pushed away from Cas. "Downstairs. Now." They immediately followed, Dean barely remembering to do up his jeans, both of them shirtless. Their scents were spoiled by fear and shock. Starting over didn't sound like a bad idea to Dean, but they had to get through with his dad first. 

They sat next to each other on the couch. Away from the warmth of what Dean was sure to be their den for the next few years, until they graduated, Dean was shivering. Cas thought about grabbing a blanket, but the thought of Dean smelling of anything other than him made the alpha in him twitch. Instead he pulled his omega close and wrapped his arm around him. John paced in front of them. Mary came in through the garage and said, "I'm home- Oh..." At the sight of her son and his best friend sitting wrapped together and her husband pacing. "Honey, what's wrong?"

"Castiel was taking advantage of our son." John growled out. 

Mary laughed. "You don't think Dean can defend himself from /Cas/?" She sat in an armchair.

"Not when he's... In this state" John blushed. 

"John, would I let our child out if I wasn't positive he was out of heat?" 

"Cas is still an Alpha and Dean's still an Omega" 

"John, they've already been scenting. All you've done is frustrate them. They know what they're doing."

"Mary-"

"Dean, take your mate upstairs. I need to speak with your father."

Dean nodded. He rushed upstairs. Once they were safely in Dean's room, Dean sat on the floor with his head in his hands. Cas knelt next to him. 

"What's the matter, pet?"

Dean shook his head, "What are we doing, Cas? We're 16! We can't mate now. What if something happens? We'd kill each other..."

"Why do you think that? Do you think I'd leave you?"

Dean nodded. 

"Why do you think that?"

"You're too good to me, Cas. You get my homework, you drive me around, you offer to mate with me! Why would you stick around for me? You could have any pretty little omega out there... Why me?"

"You really believe that, don't you? Dean, I do that shit because I love you. Because ever since I manifested, all I ever wanted was you. Even without knowing your designation. You are fantastic. And your scent... God, when I smelled your heat... I've never smelled anything better. I can't imagine what it smelled like in here." Cas murmured, nuzzling his mate's neck. Dean looked up at Cas. 

"You serious?" 

"Deadly"

Dean pressed an almost chaste kiss to Castiel's lips. He lays back on the bed and Cas curls beside him. They stayed like that for hours staring at each other, just touching and breathing, sometimes kissing, never talking, they already knew each other so well. Soon, Cas drifts off to sleep and Dean curls closer to him, burying his face in Cas's chest. When Cas wakes up to find his mate wrapped in a tiny ball against him, he smiles and strokes a hand through Dean's hair. Dean's stomach growls. Cas chuckles. "Come on, pet. Let's go get dinner. It's nearly 6, I'm sure your mother made something excellent."

Dean rolls out of bed and slips on Cas's shirt, tossing his own in Cas's direction. "We have to be decent this time." He smirks.

Cas pulls on his shirt and takes Dean's hand as they walk down the stairs. They turn the corner into the kitchen and find themselves face to face with both of their parents. John and Mary on one side of the table, Chuck and Becky on the other, Sam at the end. Obviously they weren't expecting the teenagers to join them. 

Mary is the first to speak up. "The pasta's on the stove and there's bread in the warming drawer." 

"Thanks, Mom." Dean said, carefully edging around the table without dropping Cas' hand. All four sets of parental eyes were following them. Getting down two plates, Dean served a portion for both him and Cas, whose arms were wrapped around his waist and chin setting on Dean's shoulder. Upon turning around and notice the parents eyes, Dean said "What's going on?" He sat next to Cas at the other end of the table from Sam.

Chuck is the one that breaks the silence. "We just thought you'd be fucking each other's brains out by now."

"Charles! Language!" Becky says, covering Sam's ears. 

"Aunt Becky, get off!" Sammy squirms.

Dean and Cas blush simultaneously. They both try to say something but any and all words get caught in their throats. Chuck starts laughing quietly to himself, John appears to be glaring daggers at him. The group dissolves into an extremely awkward silence. Dean and Cas finish first and Dean puts the dishes in the sink. As they begin to leave, Chuck calls after them "use protection!"

Dean slams the door behind them. "God, what is their problem?" 

Cas rubs his shoulders, "It's okay, pet, they just want to protect us."

"They don't want us to mate..." Dean mumbled. Pulling Cas's arms around his middle.

He feels Cas smile against his back, "Well, let's make sure they can't separate us." He pushes Dean down onto the bed and removes his shirt. Dean pulled of his own and started on his jeans. He managed to get them undone by the time Cas got out of his. Cas grabbed the waist and ripped them and Dean's boxers down. Dean tried to cover himself but Cas was having none of it. Grabbing Dean's wrists and pinning them above his head he growled out, "No. You do not get to hide from me, Dean Winchester.  Not after you hid this from me for far too long. You are mine." He caught Dean's lips in a bruising kiss. Dean whimpered under the force of it. Cas continued to hold Dean's wrists in one hand and used the other to slip around his back and pull his mate against him. The slide of their skin together caused them to let out a collective moan. Dean felt slick begin to leak out of him. Castiel could tell something had changed. Dean had tensed under him. Then he smelled it. That delicious smell of his omega. Cas growled against  Dean's lips and released his hands in favor of dipping his fingers in the sweet slick. "Gods, Cas..." Dean sighed. He couldn't imagine how he could be more content. He had his alpha with him. His alpha wanted him. He alpha was covering him in his scent so all other alphas would know to back off, because Dean was his omega. No one else's. Dean bucked against Cas and their erections ground together. He realized how he could be more content. "Please, Cas... Claim me" The alpha froze. This wasn't the way this was supposed to work. An alpha didn't claim their omega until they were in heat. Dean wouldn't be in heat for another 3 months. You courted your mate during that time, then you scented just before their heat. Castiel had done this all backwards, but the idea of Dean being bound to him had been too exciting to ignore. He knew he couldn't claim the omega outside of his heat. It just didn't work like that. That being said, he couldn't resist taking the man beneath him. "Are you sure, Dean? I can't claim you now, but are you sure you want this now? We can wait until your next heat, I don't mind waiting for you" Cas buried his face into Deans neck where the scent glands would stand out during heat. He couldn't imagine how hard it would be to walk away if Dean told him no. Especially after his reaction to the omegas scent the first time. But he would. He would never hurt his mate in anyway.

In answer, Dean wrapped his legs around Cas and tried to pull him into his body. "Yes, Cas, please!" Castiel steadied himself and Dean, then pushed into his mate. The omega let out a satisfied moan. Cas held his breath until he was fully seated inside Dean. They wound around each other so completely. When Cas began to move they both realized they couldn't last long. Being 16 and virgins, every thrust brought them impossibly closer. It wasn't very long at all before they fell over it together. Cas stayed deep inside Dean as the omega rode out his orgasm, feeling him quiver around his cock. When he did pull out, he snuck into the bathroom for a cloth and cleaned his mate up. Dean was dozing now, but Castiel couldn't get over the state of their den. It was haphazard at best, he could tell Dean had tried very hard to make it acceptable. Cas looked fondly over at the omega, curled into the blankets, and began rearranging furniture. If this was going to be their home until they went to college, it was going to have to be more organized than this.

 


End file.
